#include <iostream>
#include <algorithm>

using namespace std;

const int N = 2e5 + 10;

typedef long long LL;
int n, c;
LL a[N], ret, b;

int main()
{
    cin >> n >> c;
    for(int i = 1; i <= n; i++) cin >> a[i];
    sort(a + 1, a + 1 + n);

    for(int i = 2; i <= n; i++)
    {
        b = a[i] - c;
        ret += upper_bound(a + 1, a + i, b) - lower_bound(a + 1, a + i, b);
    }
    cout << ret << endl;
    return 0;
}